v3 is actually a complete rewrite of v2 and will eventually replace v2. v2 is therefore legacy and you should avoid using it if possible.

Most linux distro comes with python as standard.

Python works example the same way on all linux and windows platforms.

To install python on windows, you need to download the appropriate msi installer which you can find on the official python website website. Download the 6b-bit msi windows installer if you have a 64-bit windows OS.

during the install process, it will create a new python folder directly under the c:\ rather than in the program folders, this is so that python can circumvent some windows based limitations.